TW202400706A - Thermally conductive composition, thermally conductive grease and thermally conductive sheet - Google Patents

Abstract

This thermally conductive resin composition contains a matrix resin and thermally conductive particles. The thermally conductive particles contain: thermally conductive particles A, which have been surface treated in advance with a surface treatment agent having an aromatic hydrocarbon group; and thermally conductive particles B, which have been surface treated in advance with a surface treatment agent having an aliphatic hydrocarbon group. The thermally conductive particles A and/or thermally conductive particles B are preferably at least one type of inorganic particles selected from the group consisting of plate-like particles and polyhedral particles. Provided by this configuration are a thermally conductive composition, a thermally conductive grease and a thermally conductive sheet which have an appropriate viscosity and high thermal conductivity and in which a decrease in the steady state value of compressive load is suppressed.

Description

Thermal conductive composition, thermal conductive grease and thermal conductive sheet

The present invention relates to a thermally conductive composition, thermally conductive grease and thermally conductive sheet suitable for intervening between a heating part and a heat sink of an electrical or electronic component.

In recent years, the performance of semiconductors such as CPUs has improved dramatically, and the amount of heat generated has also increased. Therefore, heat sinks are attached to electronic components that generate heat, and thermally conductive sheets are used to improve the adhesion between semiconductors and heat sinks. With the miniaturization, high performance, and high integration of machines, thermally conductive sheets are required to be soft and have high thermal conductivity. Conventionally, Patent Documents 1 to 4 and the like have been proposed as thermally conductive sheets. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Publication No. 2021-518466 [Patent Document 2] Japanese Publication No. 2020-137970 [Patent Document 3] Japanese Publication No. 2018-088416 [Patent Document 4] Japanese Patent Application Publication No. 2016-216523

However, if the conventional thermally conductive composition contains thermally conductive particles surface-treated with a surface treatment agent containing an aliphatic hydrocarbon functional group, there will be a problem of reduced viscosity. The viscosity of thermally conductive particles that have been surface-treated with a surface treatment agent of a family of hydrocarbon functional groups will be too high. Although the stability of the compressive load can be prevented from decreasing, there is a problem of increased viscosity.

In order to solve the above-mentioned conventional problems, the present invention provides a thermally conductive composition, a thermally conductive grease, and a thermally conductive sheet that have high thermal conductivity, can suppress a decrease in the compression load stability value, and have an appropriate viscosity.

The thermally conductive composition of the present invention is a thermally conductive resin composition containing a matrix resin and thermally conductive particles. The thermally conductive particles include thermally conductive particles A that have been previously surface-treated with a surface treatment agent having an aromatic hydrocarbon group, and Thermal conductive particles B are surface-treated in advance with a surface treatment agent having an aliphatic hydrocarbon group.

The thermally conductive grease of the present invention uses the above-mentioned thermally conductive composition as grease.

The thermally conductive sheet of the present invention has the above-mentioned thermally conductive composition molded into the sheet.

The present invention contains matrix resin and thermally conductive particles, and includes thermally conductive particles A surface-treated with a surface treatment agent having an aromatic hydrocarbon group, and thermally conductive particles A surface-treated with a surface treatment agent having an aliphatic hydrocarbon group. Particle B can provide: a thermally conductive composition, a thermally conductive grease and a thermally conductive sheet with high thermal conductivity, which can suppress the decrease in the compression load stability value and has an appropriate viscosity.

The present invention is a thermally conductive composition containing matrix resin and thermally conductive particles. The matrix resin is preferably a thermosetting resin such as silicone rubber, silicone rubber, acrylic rubber, fluorine rubber, epoxy resin, phenol resin, unsaturated polyester resin, melamine resin, acrylic resin, silicone resin, fluorine resin, etc. Among them, polysiloxane is preferred, and elastomer, gel, putty, grease, etc. are preferred. Elastomers and gels can also be sheet-formed. Regarding the curing system of silicone resin, any curing method such as peroxide curing reaction, addition curing reaction, condensation curing reaction, etc. can be used. Silicone resin is preferred because of its high heat resistance. In addition, since it is not corrosive to the surrounding area, has few by-products discharged out of the system, and is reliably hardened to a deep location, the addition reaction type is preferred.

At least one of the thermally conductive particles A and B is preferably at least one inorganic particle selected from the group consisting of plate-shaped and polyhedral-shaped particles. More preferably, the thermally conductive particles A and B are at least one inorganic particle selected from the group consisting of plate-shaped and polyhedral-shaped particles. By this, high thermal conductivity can be obtained. The preferred thermal conductivity of the thermally conductive composition of the present invention is 0.5-20W/mK, more preferably 1-15W/mK.

The above-mentioned thermally conductive particles have been surface-treated with a surface treatment agent in advance, including thermally conductive particles A that have been surface-treated with a surface treatment agent having an aromatic hydrocarbon group and thermally conductive particles A that have been surface-treated with a surface treatment agent having an aliphatic hydrocarbon group. Particle B. The thermally conductive particles A are 50 to 1,500 parts by mass relative to 100 parts by mass of the matrix resin, more preferably 100 to 1,200 parts by mass, and still more preferably 150 to 1,000 parts by mass. The thermally conductive particles B are 50 to 1,500 parts by mass, more preferably 100 to 1,200 parts by mass, and still more preferably 150 to 1,000 parts by mass relative to 100 parts by mass of the matrix resin. In this way, better thermal conductivity can be obtained.

The above-mentioned surface treatment agent having an aromatic hydrocarbon group is preferably an organosilane compound represented by the chemical formula: R ²¹ SiR ²² _x (OR ²³ ) _{3 - x} or an organosilane compound containing an organosiloxane (where R ²¹ is carbon The monovalent aromatic hydrocarbon group in numbers 1 to 18 which may contain a double bond is a monovalent substituent represented by the following chemical formula (1), chemical formula (2), chemical formula (3) or chemical formula (4). (Chemical formula 1 ) R ²⁴ _y R ²² _{3 - y} SiOR ²⁵ - (C _n H _2n ) _p (1) (Chemical Formula 2) [(R ²³ O) _{3 - z} R ²² _z Si] - (C _n H _2n ) _p R ²⁵ (C _n H _2n ) _p (2) (Chemical formula 3) [(R ²³ O) _{3 - z} R ²² _z SiO] - R ²⁵ (3) (Chemical formula 4) [(R ²³ O) _{3 - z} R ²² _z Si]-R ²⁶ (4) Among them, R ²² is a methyl group. R ²³ is a hydrocarbon group with 1 to 4 carbon atoms, which may be the same or different. R ²⁴ is a hydrocarbon group with 1 to 4 carbon atoms or a phenyl group, which may also contain Double bond. R ²⁵ is a divalent polysiloxane of (R ²⁶ ₂ SiO) _m . R ²⁶ is a divalent aromatic hydrocarbon group with 6 to 30 carbon atoms, and may also contain a divalent aliphatic hydrocarbon group with 1 to 4 carbon atoms. . x=1~2, y=1~3, z=0~3, n=an integer from 1 to 4, m=an integer from 1 to 20, p=0 or 1).

The above-mentioned surface treatment agent having an aromatic hydrocarbon group is preferably selected from phenyltrimethoxysilane, benzyltriethoxysilane, phenethyltriethoxysilane, phenylpropyltrimethoxysilane, and naphthyltrimethylsilane. Oxysilane, anthryltrimethoxysilane, bis(trimethoxysilyl)benzene, bis(trimethoxysilylethyl)benzene, two-terminal trimethoxysilyl polymethylphenylsiloxane oligomer At least one compound in the group consisting of a single-terminal trimethoxysilyl polymethylphenylsiloxane oligomer and a single-terminal trimethoxysilyl ethyl polymethylphenylsiloxane oligomer.

Regarding the thermally conductive particles A, the amount of the surface treatment agent having an aromatic hydrocarbon group is preferably 0.01 to 10.0 parts by mass, more preferably 0.05 to 8.0 parts by mass, and still more preferably 0.1, based on 100 parts by mass of the thermally conductive particles. ~6 parts by mass.

The above-mentioned surface treatment agent with an aliphatic hydrocarbon group is preferably an organosilane compound represented by the chemical formula: R ¹¹ SiR ¹² _x (OR ¹³ ) _{3 - x} or an organosilane compound containing an organosiloxane (where R ¹¹ is carbon The monovalent aliphatic hydrocarbon group of numbers 1 to 18 which may contain a double bond is a monovalent substituent represented by the following chemical formula (5), chemical formula (6), chemical formula (7) or chemical formula (8). (Chemical formula 5) R ¹⁴ _y R ¹² _{3 - y} SiOR ¹⁵ (C _n H _2n ) _p (5) (Chemical Formula 6) [(R ¹³ O) _{3 - z} R ¹² _z Si] - (C _n H _2n ) _p R ¹⁵ (C _n H _2n ) _p (6) (Chemical Formula 7) [(R ¹³ O) _{3 - z} R ¹² _z SiO] - R ¹⁵ (7) (Chemical Formula 8) [(R ¹³ O) _{3 - z} R ¹² _z Si]-R ¹⁶ (8) Among them, R ¹² is a methyl group. R ¹³ is an aliphatic hydrocarbon group with 1 to 4 carbon atoms, which may be the same or different. R ¹⁴ is an aliphatic hydrocarbon group with 1 to 4 carbon atoms, or Contains double bonds. R ¹⁵ is a divalent polysiloxane of (R ¹² ₂ SiO) _m . R ¹⁵ is an aliphatic hydrocarbon group having 1 to 4 carbon atoms. R ¹⁶ is a divalent aliphatic hydrocarbon group having 1 to 4 carbon atoms. x=1~2, y=1~3, z=0~3, n=an integer from 1 to 4, m=an integer from 1 to 20, p=0 or 1).

The above-mentioned surface treatment agent having an aliphatic hydrocarbon group is preferably selected from the group consisting of methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane (including normal and iso), butyltrimethoxysilane (including Normal, iso), hexyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, octadecyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, ene Propyltrimethoxysilane, methyltriisopropoxysilane, bis(trimethoxysilyl)ethane, bis(trimethoxysilyl)octane, two-terminal trimethoxysilyl polysiloxane oligo At least one compound in the group consisting of a single-terminal trimethoxysilyl polydimethylsiloxane oligomer and a single-terminal trimethoxysilyl ethyl polydimethylsiloxane oligomer.

Regarding the thermally conductive particles B, the amount of the surface treatment agent having an aliphatic hydrocarbon group is preferably 0.01 to 10.0 parts by mass, more preferably 0.05 to 8.0 parts by mass, and even more preferably 0.1 to 8.0 parts by mass relative to 100 parts by mass of the thermally conductive particles. 6 parts by mass.

The thermally conductive particles A are preferably 10 to 90 mass%, more preferably 20 to 80 mass%, and still more preferably 30 to 70 mass% based on 100 mass% of the thermally conductive particles. Moreover, with respect to 100 mass % of thermally conductive particles, the thermally conductive particles B are preferably 90 to 10 mass%, more preferably 80 to 20 mass%, and still more preferably 70 to 30 mass%.

The thermally conductive grease of the present invention is composed of the above-mentioned thermally conductive resin composition. Furthermore, the thermally conductive sheet of the present invention is obtained by molding the above-mentioned thermally conductive resin composition into a sheet.

When an addition reaction type polysiloxane composition (unhardened composition) is used as an example of the present invention, a composition having the following composition is preferred. A: Thermal conductive particles surface-treated with a surface treatment agent having an aromatic hydrocarbon group: 50 to 1500 parts by mass relative to 100 parts by mass of the matrix resin B: Thermal conductive particles surface-treated with a surface treatment agent having an aliphatic hydrocarbon group: 50 to 1500 parts by mass relative to 100 parts by mass of the matrix resin C. Matrix resin composition The matrix resin component includes the following (C1) and (C2). Let (C1) + (C2) be 100 mass%. (C1) Linear organopolysiloxane containing at least 2 alkenyl groups bonded to silicon atoms in one molecule (C2) Cross-linking component: Organohydrogen polysiloxane containing at least 2 hydrogen atoms bonded to silicon atoms in one molecule is less than 1 mole of alkenyl groups bonded to silicon atoms in component A above. 1 mole In addition to the above-mentioned components (C1) and (C2), an organopolysiloxane without a reactive group may also be included. D. Platinum metal catalyst: relative to the matrix resin component, the amount is 0.01 to 1000 ppm in mass units. E. Other additives: hardening retardant, colorant, etc.; any amount, silane coupling agent

Each component is explained below. (1) Base polymer component (C1 component) The base polymer component is an organic polysiloxane containing more than two alkenyl groups bonded to silicon atoms in one molecule. An organic polysiloxane containing more than two alkenyl groups is Siloxane is the main agent (base polymer component) in the silicone rubber composition of the present invention. This organopolysiloxane has two alkenyl groups in one molecule, such as vinyl groups and allyl groups, with carbon atoms of 2 to 8 (especially 2 to 6) bonded to silicon atoms. Due to workability, hardening properties, etc., the viscosity should be 10 to 1,000,000 mPa·s at 25°C, especially 100 to 100,000 mPa·s. Specifically, an organopolysiloxane represented by the following Chemical Formula 9 containing two or more alkenyl groups bonded to a silicon atom at a molecular chain terminal in one molecule is used. The side chain is a linear organopolysiloxane terminated by an alkyl group. Due to workability, hardening properties, etc., the viscosity at 25°C is preferably 10 to 1,000,000 mPa·s. In addition, this linear organopolysiloxane may also contain a small amount of branched structure (trifunctional siloxane unit) in the molecular chain. (Chemical Formula 9)

In the formula, R ¹ is the same or different unsubstituted or substituted monovalent hydrocarbon group without an aliphatic unsaturated bond, R ² is an alkenyl group, and k is 0 or a positive integer. Here, as ^R1 , the unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond is, for example, preferably one having 1 to 10 carbon atoms, especially one having 1 to 6 carbon atoms. Specific examples include A Alkyl groups such as ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl, neopentyl, hexyl, cyclohexyl, octyl, nonyl, decyl, etc.; phenyl , tolyl, stubble, naphthyl and other aryl groups; benzyl, phenethyl, phenylpropyl and other aralkyl groups; and part or all of the hydrogen atoms of these groups are replaced by fluorine, bromine, chlorine and other halogen atoms , cyano group and other substituted ones, such as chloromethyl, chloropropyl, bromoethyl, trifluoropropyl and other halogen-substituted alkyl groups, cyanoethyl, etc. The alkenyl group of R ² is preferably one having 2 to 6 carbon atoms, particularly 2 to 3 carbon atoms. Specific examples include vinyl, allyl, propenyl, isopropenyl, butenyl, and isobutylene. group, hexenyl, cyclohexenyl, etc., preferably vinyl. In Chemical Formula 9, generally speaking, k is 0 or a positive integer satisfying 0≦k≦10000, preferably 5≦k≦2000, and more preferably an integer satisfying 10≦k≦1200.

The organopolysiloxane as the C1 component can also be used together, for example, having 3 or more (usually 3 to 30, preferably about 3 to 20) carbon atoms such as vinyl and allyl groups in one molecule. Organopolysiloxanes with alkenyl groups of 2 to 8 (especially 2 to 6) bonded to silicon atoms. The molecular structure can be any molecular structure such as linear, cyclic, branched, or three-dimensional network. It is preferred that the main chain is composed of two repeating organosiloxane units, and the two ends of the molecular chain are terminated by three organosiloxy groups and the viscosity at 25°C is 10~1000000mPa·s, especially 100~100000mPa·s. Linear organopolysiloxane.

The alkenyl group can be bonded to any part of the molecule. For example, it may include silicon atoms bonded to the end of the molecular chain or to the non-end of the molecular chain (midway through the molecular chain). Among them, it is a linear organopolysiloxane represented by the following chemical formula 10. The linear organopolysiloxane has 1 to 3 alkenyl groups on the silicon atoms at both ends of the molecular chain, but when the bond When the total number of alkenyl groups bonded to the silicon atom at the end of the molecular chain does not reach 3, there is at least one alkenyl group bonded to the silicon atom at the non-terminal end of the molecular chain (midway through the molecular chain) (for example, as Substituents in the two organosiloxane units), as mentioned above, due to workability, hardening properties, etc., the viscosity at 25°C is preferably 10 to 1,000,000 mPa·s. In addition, this linear organopolysiloxane may also contain a small amount of branched structure (trifunctional siloxane unit) in the molecular chain.

(Chemical formula 10)

In the formula, R ³ are the same or different unsubstituted or substituted monovalent hydrocarbon groups, and at least one of them is an alkenyl group. R ⁴ are the same or different unsubstituted or substituted monovalent hydrocarbon groups without aliphatic unsaturated bonds, R ⁵ is an alkenyl group, and l and m are 0 or positive integers. Here, the monovalent hydrocarbon group of R ³ is preferably one having 1 to 10 carbon atoms, particularly 1 to 6 carbon atoms. Specific examples include methyl, ethyl, propyl, isopropyl, butyl, Alkyl groups such as isobutyl, tertiary butyl, pentyl, neopentyl, hexyl, cyclohexyl, octyl, nonyl, and decyl; aryl groups such as phenyl, tolyl, stubble, naphthyl, etc.; benzyl , phenethyl, phenylpropyl and other aralkyl groups; vinyl, allyl, propenyl, isopropenyl, butenyl, hexenyl, cyclohexenyl, octenyl and other alkenyl groups, or the like Part or all of the hydrogen atoms of the base are substituted with halogen atoms such as fluorine, bromine, chlorine, or cyano groups, such as halogen-substituted alkyl groups such as chloromethyl, chloropropyl, bromoethyl, trifluoropropyl, etc. Or cyanoethyl, etc. In addition, the monovalent hydrocarbon group of R ⁴ is preferably one having 1 to 10 carbon atoms, especially one having 1 to 6 carbon atoms. Examples thereof include the same specific examples as those of R ¹ above, except that an alkenyl group is not included. The alkenyl group of R ⁵ is preferably one having 2 to 6 carbon atoms, and particularly one having 2 to 3 carbon atoms. Specifically, the alkenyl group is the same as R ² of the above-mentioned Chemical Formula 9, and preferably is a vinyl group. Generally speaking, l and m are 0 or a positive integer that satisfies 0＜l＋m≦10000, preferably 5≦l＋m≦2000, more preferably 10≦l+m≦1200, and satisfies 0＜l/(l+m)≦0.2, Preferably, it is an integer of 0.0011≦l/(l+m)≦0.1.

(2) Cross-linked component (C2 component) The organohydrogen polysiloxane of the C2 component of the present invention functions as a cross-linking agent, and a cured product is formed by an addition reaction (hydrosilylation) between the SiH group in this component and the alkenyl group in the C1 component. As long as the organohydrogen polysiloxane has two or more hydrogen atoms (that is, SiH groups) bonded to silicon atoms in one molecule, any one can be used. The organohydrogen polysiloxane is The molecular structure can be any of linear, cyclic, branched, or three-dimensional network structures. Regarding the number of silicon atoms in one molecule (that is, the degree of polymerization), 2 to 1000 can be used, especially around 2 to 300. By.

The position of the silicon atom to which the hydrogen atom is bonded is not particularly limited. It can be at the end of the molecular chain or at the non-end of the molecular chain (midway through the molecular chain). Examples of the organic group other than hydrogen atoms bonded to the silicon atom include unsubstituted or substituted monovalent hydrocarbon groups having no aliphatic unsaturated bond and the same as R ¹ of the above-mentioned Chemical Formula 9.

Examples of the organohydrogen polysiloxane as the C2 component include the following structures. (Chemical Formula 11)

In the above formula, R ⁶ is the same or different alkyl group, phenyl group, epoxy group, acryl group, methacryl group, alkoxy group, or hydrogen atom, and at least two of them are hydrogen atoms. L is an integer from 0 to 1,000, especially an integer from 0 to 300, and M is an integer from 1 to 200.

(3) Catalyst component (D component) As the catalyst component of component D, a catalyst used for silicon hydrogenation reaction can be used. Examples include platinum black, platinum chloride, chloroplatinic acid, reactants of chloroplatinic acid and monohydric alcohols, complexes of chloroplatinic acid and olefins or vinylsiloxane, platinum diacetate acetate and other platinum-based contacts. media; palladium-based catalysts, rhodium-based catalysts and other platinum group metal catalysts.

(4) Thermal conductive particles (components A and B) Thermal conductive particles of components A and B are preferably aluminum oxide, zinc oxide, magnesium oxide, aluminum nitride, boron nitride, aluminum hydroxide, silicon carbide or silicon dioxide. wait. Various shapes such as spherical, scaly, plate, and polyhedral shapes can be used. The specific surface area of the thermally conductive filler is preferably in the range of 0.06 to 15 m ² /g. The specific surface area is the BET specific surface area, and the measurement method is in accordance with JIS R1626 (1996). When the average particle diameter is used, it is preferably in the range of 0.1 to 100 μm. The particle size is measured by laser diffraction light scattering method to determine the D50 (median particle size) of the cumulative particle size distribution based on the volume basis. As this measuring device, there is, for example, a laser diffraction/scattering particle distribution measuring device LA-950S2 manufactured by Horiba Manufacturing Co., Ltd. Among them, plate-shaped alumina, plate-shaped boron nitride, polyhedral alumina, polyhedral aluminum nitride, fused spherical alumina, particulate round alumina, etc. are preferred. Thermal conductive particles are also called thermally conductive fillers or just fillers.

The surface treatment of the thermally conductive particles by a silane coupling agent is preferably a dry treatment in which a high-speed stirring device such as a Henschel mixer is used. After the thermally conductive particles are placed in a container, the surface treatment agent is added to the mixture. This surface treatment may also be performed by a wet treatment method in which a solvent is used to mix a surface treatment agent in a slurry form and the solvent is evaporated and removed. Since the treatment operation is simple, dry treatment is preferred. It is also possible to perform heating and pressure reduction operations simultaneously during surface treatment by high-speed rotation. In addition, in order to terminate the treatment reaction, a step of heating at 80 to 180°C for 1 to 24 hours may also be included.

The amount of silane required to treat the surface of thermally conductive inorganic particles can be calculated by the following formula. Amount of silane (g) = Amount of thermally conductive inorganic powder (g) × Specific surface area of thermally conductive inorganic powder (m ² /g) / Minimum covered area of silane (m ² /g) "Minimum covered area of silane" It is calculated by the following formula. Minimum coating area of silane (m ² /g) = (6.02× ^{10 23} ) × (13×10 ^{- 20} ) / molecular weight of silane. In the above formula, 6.02×10 ²³ : Avogadro constant 13×10 ^{- 20} : The area covered by one molecule of silane (0.13nm ² ). The necessary amount of silane is preferably 0.5 to 10 times the "minimum silane coverage area" (hereinafter also referred to as Amin.), more preferably 0.8 to 5 times or less. Thereby, the filling ability of the thermally conductive inorganic particles into the matrix resin can be improved.

(5) Other additives In the composition of the present invention, ingredients other than the above may be blended if necessary. For example, heat resistance enhancers such as hematite oxide, titanium oxide, and cerium oxide; flame resistance additives; hardening retarder, etc. can also be added. For coloring and toning, organic or inorganic pigments can also be added. The above-mentioned silane coupling agent may also be added.

The following uses diagrams to illustrate. In the following drawings, the same symbols represent the same thing. FIG. 1 is a schematic cross-sectional view of a heat dissipation structure 10 incorporating a thermally conductive sheet according to an embodiment of the present invention. The thermally conductive sheet 11b dissipates heat generated by electronic components 13 such as semiconductor elements, and is fixed to the main surface 12a of the heat spreader 12 opposite to the electronic component 13, and is sandwiched between the electronic component 13 and the heat spreader 12. between. In addition, the thermal conductive sheet 11 a is sandwiched between the heat sink 12 and the heat sink 15 . In addition, the heat conduction sheets 11 a and 11 b together with the heat sink 12 constitute a heat dissipation member that dissipates the heat of the electronic component 13 . The heat sink 12 is formed in a square plate shape, for example, and has a main surface 12a facing the electronic component 13 and a side wall 12b standing along the outer edge of the main surface 12a. The heat sink 12 is provided with a heat conductive sheet 11b on the main surface 12a surrounded by the side wall 12b, and is provided with a heat dissipation base 15 through the heat conductive sheet 11a on the other surface 12c opposite to the main surface 12a. The electronic component 13 is a semiconductor element such as a BGA, for example, and is built on the wiring board 14 . [Example]

Examples will be used to illustrate the following. The present invention is not limited to the examples. Various measurement methods in Examples and Comparative Examples are as follows. ＜Thermal conductivity＞ (1) Grease: Use DYNTIM device (manufactured by Siemens) and measure according to ASTM D5470:2017. (2) Tablet: Measured based on Hotdisk device (manufactured by Kyoto Electronics Industry Co., Ltd.) ISO-22007-2:2008. <Viscosity> was measured using a HAAKE MARS rheometer (manufactured by Thermo Scientific) in accordance with ASTM D1824-95:2010. ＜Compression load＞ Use a piece with a length of 15mm, a width of 15mm, and a thickness of 2mm, and measure it according to ASTM D575-91:2012 at a pressing speed of 5.0mm/min. ＜Hardness＞ The hardness of the thermally conductive polysiloxane sheet is set to Asker-C specified in JIS K7312:1996.

1 Raw materials (1) Thermal conductive filler ・F1: Plate-shaped alumina (trade name AP-10: average particle diameter 9 μm, BET specific surface area 1.5m ² /g, aspect ratio 15, manufactured by DIC Co., Ltd.) ・F2: Plate-shaped boron nitride (trade name HSL: average particle diameter 35 μm, BET specific surface area 2 m ² /g, aspect ratio 38, manufactured by Dandong Chemical Engineering Institute Co., Ltd.) is shown in Figure 2.・F3: Polyhedral aluminum oxide (trade name AH40S: average particle diameter 32 μm, BET specific surface area 0.1 m ² /g or less, manufactured by DIC Co., Ltd.) ・F4: Polyhedral aluminum nitride (trade name HF-20: average particle size Diameter 19 μm, BET specific surface area 0.2 m ² /g, manufactured by Tokuyama Co., Ltd.) ・F5: Polyhedral alumina (trade name AA-3: Average particle diameter 3.5 μm, BET specific surface area 0.6 m ² /g, Sumitomo Chemical joint stock limited company), as shown in Figure 3.・F6: Molten spherical alumina (trade name AZ35-75R: average particle diameter 38 μm, BET specific surface area 0.2 m ² /g, manufactured by Nippon Steel Chemical Materials Co., Ltd.), as shown in Figure 4.・F7: Fine particle round alumina (trade name AKP-30: average particle diameter 0.3 μm, BET specific surface area 7.4 m ² /g, manufactured by Sumitomo Chemical Co., Ltd.), as shown in Figure 5. (2) Surface treatment agent <Surface treatment agent with aromatic hydrocarbon group> ・S1: Phenyltrimethoxysilane (trade name KBM-103: Chemical formula C ₆ H ₅ Si (OCH ₃ ) ₃ , molecular weight 198.3, Shin-Etsu Chemical Industry Co., Ltd.) ・S2: Benzyltriethoxysilane (trade name SIB0971.0: Chemical formula C ₆ H ₅ CH ₂ Si (OC ₂ H ₅ ) ₃ , molecular weight 254.4, Galest Corporation) <With Aliphatic hydrocarbon-based surface treatment agent > ・S3: Decyltrimethoxysilane (trade name OFS-6210: chemical formula n-C ₁₀ H ₂₁ Si (OCH ₃ ) ₃ , molecular weight 262.5, manufactured by Dow Toray Co., Ltd.)・S4: Isobutyltriethoxysilane (trade name OFS-6403: chemical formula iso-C ₄ H ₉ Si (OC ₂ H ₅ ) ₃ , molecular weight 178.3, manufactured by Dow Toray Co., Ltd.) ・S5: α -Triethoxysilyl ethyl ester, β-n-butyl (polydimethylsiloxane) (trade name MCR-XT11: chemical formula C ₄ H ₉ (CH ₃ ) ₂ SiO - (Si (CH ₃ ) ₂ O) _n -Si (CH ₃ ) ₂ -C ₂ H ₄ -Si (OC ₂ H ₅ ) ₃ , viscosity: 16-24cSt, manufactured by Galest Co., Ltd.) ・S6: Methyltrimethoxysilane (trade name) : OFS-6070: Chemical formula CH ₃ Si (OCH ₃ ) ₃ , molecular weight 136.2, manufactured by Dow Toray Co., Ltd.)

2. Surface treatment of filler Use 100.0g of plate-shaped thermally conductive filler (such as the above F1), and 0.35g of phenyltrimethoxysilane (molecular weight = 198.3) as a surface treatment agent (such as the above S1), and use Wonder Crusher WC-3 (OSAKA CHEMICAL Co., Ltd. company) performs dry surface treatment. Furthermore, heat treatment was performed at 120° C. for 12 hours to obtain a surface-treated thermally conductive filler. For other fillers, perform the same treatment with the compositions shown in Tables 1 and 2. Using thermogravimetric analysis, the adhesion amount of each surface treatment agent was determined. Since part of the surface treatment agent (silane compound) added by heat treatment volatilizes, the amount of remaining surface treatment agent adhered was confirmed by thermogravimetric analysis.

[Table 1] Silane classification Treatment with aromatic hydrocarbon-containing silane Sample number F1/S1 F2/S1 F2/S2 F3/S1 F4/S1 F5/S1 F6/S1 F7/S1 Filler No. F1 F2 F2 F3 F4 F5 F6 F7 filler material Alumina Boron nitride Boron nitride Alumina aluminum nitride Alumina Alumina Alumina Filler shape plate shape plate shape plate shape Polyhedron Polyhedron Polyhedron spherical round D50(μm) 10 35 35 32 19 3.4 38 0.27 BET (m ² /g) 1.5 2.0 2.0 0.1 or less 0.2 0.5 0.2 6.7 Filling amount (g) 100 100 80 100 80 100 200 150 Treatment agent No. S1 S1 S2 S1 S1 S1 S1 S1 Amount of treatment agent (g) 0.38 1.00 0.80 0.20 0.27 0.14 0.13 2.80 Multiples of Amin 1 2 2 10 2 1 2 2 Treatment dose (*1) (wt%) 0.16 0.07 0.06 (*2) (*2) 0.04 0.01 0.52 (*1) Calculated based on TGA results. (*2) Stable measured values cannot be obtained.

[Table 2] Silane classification Treatment with aliphatic hydrocarbon-containing silane Sample number F1/S3 F2/S3 F2/S4 F2/S5 F3/S3 F4/S3 F5/S3 F6/S3 F7/S3 F7/S6 F7/S5 Filler No. F1 F2 F2 F2 F3 F4 F5 F6 F7 F7 F7 filler material Alumina Boron nitride Boron nitride Boron nitride Alumina aluminum nitride Alumina Alumina Alumina Alumina Alumina Filler shape plate shape plate shape plate shape plate shape Polyhedron Polyhedron Polyhedron spherical round round round D50(μm) 10 35 35 35 32 19 3.4 38 0.27 0.27 0.27 BET (m ² /g) 1.5 2.0 2.0 2.0 0.1 0.2 0.4 0.2 6.7 6.7 6.7 Filling amount (g) 100 100 80 80 100 80 150 200 150 150 150 Treatment agent No. S3 S3 S4 S5 S3 S3 S3 S3 S3 S6 S5 Amount of treatment agent (g) 0.50 1.60 0.89 2.41 0.25 0.2 0.28 0.13 3.72 1.93 7.5 Multiples of Amin 1 2 2 2 10 2 1 2 1 1 1 Treatment dose (*1) (wt%) 0.20 0.13 0.05 1.35 (*2) (*2) 0.08 0.02 1.25 0.11 3.51 (*1) Calculated based on TGA results. (*2) Stable measured values cannot be obtained.

(Examples 1 to 5, Comparative Examples 1 to 7) In this Example and Comparative Example, thermally conductive compositions were produced and evaluated. The thermally conductive filler adjusted as described above was mixed with the composition shown in Tables 3 to 4 using a rotational and orbital mixer (MAZERUSTAR KK-400W, manufactured by Kurabo Co., Ltd.) to obtain a thermally conductive composition. The viscosity and thermal conductivity of the obtained thermally conductive resin composition were measured. The silicone polymer (matrix resin) used in each Example and Comparative Example is as follows. CY52-276A/B: Two-liquid addition-hardening dimethylpolysiloxane resin (dimethylpolysiloxane) manufactured by Dow Toray Co., Ltd. SH510-500CS: Tolyl polysiloxane oil (tolyl polysiloxane) manufactured by Dow Toray Co., Ltd. SH200-110CS: Dimethyl polysiloxane oil (dimethyl polysiloxane) manufactured by Dow Toray Co., Ltd. The above conditions and results are shown in Tables 3 to 4.

[table 3] Example 1 Comparative example 1 Comparative example 2 Example 2 Example 3 Comparative example 3 Thermal conductive filler A (F1/S1) (g) 150 150 - 150 - - Thermal conductive filler A (F3/S1) (g) - 200 - - 200 - Thermal conductive filler B (F1/S3) (g) - - 150 - 150 150 Thermal conductive filler B (F3/S3) (g) 200 - 200 200 - 200 Total filler (g) 350 350 350 350 350 350 CY52-276A/B (g) 100 100 100 - - - SH510-500cs (g) - - - 100 100 100 Put in the total (g) 450 450 450 450 450 450 Proportion of filler (wt.%) 78 78 78 78 78 78 Proportion of filler (vol.%) 46 46 46 46 46 46 Viscosity (Pa-s) ^(*) 507 742 146 280 124 113 Thermal conductivity (W/mK) 1.80 1.64 1.56 1.72 1.75 1.64 (*) The viscosity is measured by mixing only liquid A of the two-liquid mixed type. This is because when liquid A and liquid B are mixed, they begin to harden and the viscosity increases even at room temperature.

[Table 4] Example 4 Comparative example 4 Comparative example 5 Example 5 Comparative example 6 Comparative example 7 Thermal conductive filler A (F2/S1) (g) 75 150 - - - - Thermal conductive filler A (F5/S1) (g) - - - 150 300 - Thermal conductive filler B (F2/S3) (g) 75 - 150 - - - Thermal conductive filler B (F5/S3) (g) - - - 150 - 300 Total filler (g) 150 150 150 300 300 300 SH200-110cs (g) 100 100 100 100 100 100 Put in the total (g) 250 250 250 400 400 400 Proportion of filler (wt.%) 60 60 60 75 75 75 Proportion of filler (vol.%) 40 40 40 43 43 43 Viscosity (Pa-s 1/s) 477 779 474 1230 Unable to measure 360 Thermal conductivity (W/mK) 1.55 1.39 1.53 2.16 Unable to measure 2.01

As can be clearly seen from Tables 3 to 4, when comparing Example 1 and Comparative Examples 1 to 2 in which the matrix resin is dimethylpolysiloxane, the composition of Example 1 has high thermal conductivity, and the viscosity does not decrease. Furthermore, when comparing Examples 2 to 3 in which the matrix resin is tolyl polysiloxane and Comparative Example 3, the compositions of Examples 2 to 3 have high thermal conductivity and there is no decrease in viscosity. In addition, when comparing Example 4 with a filler ratio of 60 wt% and Comparative Examples 4 to 5, the composition of Example 4 has high thermal conductivity, and the viscosity does not decrease. Furthermore, when Example 5 is compared with Comparative Examples 6 to 7, the composition of Example 5 has high thermal conductivity, and the viscosity does not decrease.

(Examples 6 to 8, Comparative Examples 8 to 10) In this Example and Comparative Example, thermally conductive sheets were produced and evaluated. A two-liquid heat-hardening silicone polymer is used as the matrix resin component. The component (1A) in which a base polymer component and a platinum-based metal catalyst are added in advance, and the component (1B) in which a base polymer component and a cross-linking component are added in advance are used. The plate-shaped thermally conductive filler and the non-plate-shaped inorganic filler are mixed with these base polymers using a rotation and revolution mixer. After defoaming, they are clamped on a polyester (PET) film and calendered to a thickness of 2.0mm to obtain The sample was heated and hardened by holding it at 100° C. for 15 minutes. The hardness (Asker-C), instantaneous value/steady value change of compressive load, and thermal conductivity of the obtained thermally conductive polysiloxane sheet are shown in Table 5.

[table 5] Example 6 Comparative example 8 Example 7 Comparative example 9 Example 8 Comparative example 10 Thermal conductive filler A (F2/S1) (g) - 83.3 62.5 - - - Thermal conductive filler A (F3/S2) (g) 83.3 - - - - - Thermal conductive filler A (F5/S1) (g) - - - - 100.0 - Thermal conductive filler A (F6/S1) (g) - 166.7 125.0 - 200.0 - Thermal conductive filler A (F7/S1) (g) - 83.3 - - - - Thermal conductive filler A (F2/S1) (g) - 83.3 - - - - Thermal conductive filler B (F2/S3) (g) - - - 62.5 - - Thermal conductive filler B (F2/S4) (g) 83.3 - - - - - Thermal conductive filler B (F2/S2) (g) - - 62.5 125.0 - - Thermal conductive filler B (F5/S3) (g) 166.7 - - 62.5 100.0 100.0 Thermal conductive filler B (F6/S3) (g) - - - - - 300.0 Thermal conductive filler B (F7/S3) (g) - - 62.5 62.5 - - Thermal conductive filler B (F7/S6) (g) 83.3 - - - - - Thermal conductive filler B (F7/S5) (g) - - - - 100.0 100.0 Total filler A (g) 83.3 416.6 187.5 0.0 300.0 0.0 Total filler B (g) 333.3 0.0 125.0 312.5 200.0 500.0 Total filler (g) 416.6 416.6 312.5 312.5 500.0 500.0 CY52-276A(g) 94.0 94.0 92.0 92.0 95.0 95.0 CY52-276B(g) 6.0 6.0 8.0 8.0 5.0 5.0 Put in the total (g) 516.6 516.6 412.5 412.5 600.0 600.0 Proportion of filler (wt.%) 81 81 76 76 83 83 Proportion of filler (vol.%) 57 54 50 50 55 55 Viscosity (Pa-s 1/s) 2280 891 6050 5010 38 113 Hardness (Asker-C: after 10sec) 32 twenty four twenty two 19 12 11 Thermal conductivity (W/mK) 3.36 2.29 2.48 2.40 1.52 1.46 Compression load instantaneous value, at 50% compression (N) 498 370 228 223 223 220 Compression load stability value, after 1 minute, at 50% compression (N) 298 210 114 100 86 80 Compression load, instantaneous/steady load change (%) -40 -43 -50 -55 -61 -64

As is clear from Table 5, the thermal conductivity of each example is higher and the reduction rate of the compression load stability value is smaller than that of the comparative example. If the reduction rate of the compression load stability value is small, the pressure drop in each gap between the heat source and the heat sink fins can be suppressed when the device is installed as a heat sink, thereby maintaining the heat dissipation characteristics. [Industrial availability]

The thermally conductive composition and thermally conductive sheet of the present invention are suitable for being interposed between the heating part and the heat sink of electrical and electronic components.

10:Heat dissipation structure 11a, 11b: Thermal conductive sheet 12: Radiator 13: Electronic parts 14:Wiring board 15: Cooling seat

[Fig. 1] is a schematic cross-sectional view showing a method of using the thermally conductive sheet according to one embodiment of the present invention. [Fig. 2] is a scanning electron microscope photograph (magnification: 5,000 times) of plate-shaped particles (boron nitride) according to one embodiment of the present invention. [Fig. 3] is a scanning electron microscope photograph (magnification: 3,000 times) of polyhedral particles (alumina) according to one embodiment of the present invention. [Fig. 4] is a scanning electron microscope photograph (magnification: 1,000 times) of molten spherical particles (alumina) according to one embodiment of the present invention. [Fig. 5] is a scanning electron microscope photograph (magnification: 10,000 times) of fine round particles (alumina) according to one embodiment of the present invention.

10:Heat dissipation structure

11a, 11b: Thermal conductive sheet

12:heat spreader

13: Electronic parts

14:Wiring board

15:heat sink

Claims (12)

A thermally conductive resin composition containing matrix resin and thermally conductive particles, characterized by: The thermally conductive particles include thermally conductive particles A that have been previously surface-treated with a surface treatment agent having an aromatic hydrocarbon group, and thermally conductive particles B that have been previously surface-treated with a surface treatment agent having an aliphatic hydrocarbon group. The thermally conductive resin composition of claim 1, wherein at least one of the thermally conductive particles A and B is at least one inorganic particle selected from the group consisting of plate-shaped and polyhedral-shaped. The thermally conductive resin composition of claim 1, wherein, relative to 100 parts by mass of the matrix resin, the thermally conductive particles A are 50 to 1500 parts by mass, and the thermally conductive particles B are 50 to 1500 parts by mass. The thermally conductive resin composition of claim 1, wherein the surface treatment agent having an aromatic hydrocarbon group is an organosilane compound represented by the chemical formula: R ²¹ SiR ²² _x (OR ²³ ) _{3 - x} or contains an organosiloxane Organosilane compound (where R ²¹ is a monovalent aromatic hydrocarbon group with 1 to 18 carbon atoms that may also contain a double bond, and is the following chemical formula (1), chemical formula (2), chemical formula (3) or chemical formula (4) The monovalent substituent represented is: (Chemical Formula 1) R ²⁴ _y R ²² _{3 - y} SiOR ²⁵ - (C _n H _2n ) _p (1) (Chemical Formula 2) [(R ²³ O) _{3 - z} R ²² _z Si ]-(C _n H _2n ) _p R ²⁵ (C _n H _2n ) _p (2) (Chemical Formula 3) [(R ²³ O) _{3 - z} R ²² _z SiO]-R ²⁵ (3) (Chemical Formula 4) [ (R ²³ O) _{3 - z} R ²² _z Si]-R ²⁶ (4) Among them, R ²² is a methyl group, R ²³ is a hydrocarbon group with 1 to 4 carbon atoms, which may be the same or different, and R ²⁴ is a carbon number 1 ~4 hydrocarbon group or phenyl group, may also contain double bonds, R ²⁵ is (R ²⁶ ₂ SiO) _m divalent polysiloxane, R ²⁶ is a divalent aromatic hydrocarbon group with 6 to 30 carbon atoms, may also contain Divalent aliphatic hydrocarbon group with 1 to 4 carbon atoms, x=1 to 2, y=1 to 3, z=0 to 3, n=an integer from 1 to 4, m=an integer from 1 to 20, p=0 or 1). The thermally conductive resin composition of claim 1, wherein the surface treatment agent having an aromatic hydrocarbon group is selected from the group consisting of phenyltrimethoxysilane, benzyltriethoxysilane, phenethyltriethoxysilane, benzene Propyltrimethoxysilane, naphthyltrimethoxysilane, anthracenyltrimethoxysilane, bis(trimethoxysilyl)benzene, bis(trimethoxysilylethyl)benzene, both terminal trimethoxysilyl Polymethylphenylsiloxane oligomer, single-terminal trimethoxysilyl polymethylphenylsiloxane oligomer, single-terminal trimethoxysilyl ethyl polymethylphenylsiloxane oligomer At least one compound in the group of substances. The thermally conductive resin composition of claim 1, wherein the amount of the surface treatment agent having an aromatic hydrocarbon group added to the thermally conductive particles A is 0.01 to 10.0 parts by mass relative to 100 parts by mass of the thermally conductive particles. The thermally conductive resin composition of claim 1, wherein the surface treatment agent having an aliphatic hydrocarbon group is an organosilane compound represented by the chemical formula: R ¹¹ SiR ¹² _x (OR ¹³ ) _{3 - x} or contains an organosiloxane The organosilane compound (wherein R ¹¹ is a monovalent aliphatic hydrocarbon group with a carbon number of 1 to 18 that may also contain a double bond, is the following chemical formula (5), chemical formula (6), chemical formula (7) or chemical formula (8) ), (Chemical Formula 5) R ¹⁴ _y R ¹² _{3 - y} SiOR ¹⁵ (C _n H _2n ) _p (5) (Chemical Formula 6) [(R ¹³ O) _{3 - z} R ¹² _z Si ]-(C _n H _2n ) _p R ¹⁵ (C _n H _2n ) _p (6) (Chemical Formula 7) [(R ¹³ O) _{3 - z} R ¹² _z SiO]-R ¹⁵ (7) (Chemical Formula 8) [ (R ¹³ O) _{3 - z} R ¹² _z Si]-R ¹⁶ (8) Among them, R ¹² is a methyl group, R ¹³ is an aliphatic hydrocarbon group with 1 to 4 carbon atoms, which may be the same or different, and R ¹⁴ is a carbon Aliphatic hydrocarbon groups with 1 to 4 carbon atoms may also contain double bonds. R ¹⁵ is a divalent polysiloxane of (R ¹² ₂ SiO) _m . R ¹⁵ is an aliphatic hydrocarbon group with 1 to 4 carbon atoms. R ¹⁶ is carbon. Divalent aliphatic hydrocarbon group with numbers 1 to 4, x=1 to 2, y=1 to 3, z=0 to 3, n=an integer from 1 to 4, m=an integer from 1 to 20, p=0 or 1 ). The thermally conductive resin composition of claim 1, wherein the surface treatment agent having an aliphatic hydrocarbon group is selected from the group consisting of methyltrimethoxysilane, ethyltrimethoxysilane, and propyltrimethoxysilane (including normal and isotrimethoxysilane). ), butyltrimethoxysilane (including normal and iso), hexyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, octadecyltrimethoxysilane, vinyltrimethoxysilane , vinyltriethoxysilane, allyltrimethoxysilane, methyltriisopropoxysilane, bis(trimethoxysilyl)ethane, bis(trimethoxysilyl)octane, both ends Trimethoxysilyl polysiloxane oligomer, single-terminal trimethoxysilyl polydimethylsiloxane oligomer, single-terminal trimethoxysilyl ethyl polydimethylsiloxane oligomer At least one compound in the group. The thermally conductive resin composition of claim 1, wherein the amount of the surface treatment agent having an aliphatic hydrocarbon group in the thermally conductive particles B is 0.01 to 10.0 parts by mass relative to 100 parts by mass of the thermally conductive particles. The thermally conductive resin composition of claim 1, wherein the thermally conductive particles A are 10 to 90 mass% and the thermally conductive particles B are 90 to 10 mass% relative to 100 mass% of the thermally conductive particles. A thermally conductive grease composed of the thermally conductive resin composition according to any one of claims 1 to 10. A thermally conductive sheet formed by molding the thermally conductive resin composition according to any one of claims 1 to 10.